<template>
  <div>
    <span>全选:</span>
    <input type="checkbox" v-model="isAll"/>
    <button @click="fn">反选</button>
    <ul>
      <li v-for="(item, index) in arr" :key="index">
        <input type="checkbox" v-model="item.c"/>
        <span>{{ item.name }}</span>
      </li>
    </ul>
  </div>
</template>

<script>
export default {
  data() {
    return {
      arr: [
        {
          name: "猪八戒",
          c: false,
        },
        {
          name: "孙悟空",
          c: false,
        },
        {
          name: "唐僧",
          c: false,
        },
        {
          name: "白龙马",
          c: false,
        },
      ],
    };
  },

  // 计算属性
  computed: {
      isAll: {
          get (){
            // 小复选框 影响 全选框
             return this.arr.every(item => item.c === true)
          },
          set(val) {
             console.log(val);
              
              // 全选框 影响 小复选框
             this.arr.forEach(item => item.c = val)
          }
      }
  },

  methods: {
    fn() {
       this.arr.forEach(item => item.c = !item.c)
    }
  }
};
</script>